My thong-fetish is so intense that i find an ass with a thong at least 90% sexier than a fully naked ass(well, technically an ass in a thong already is fully exposed, that's also what makes it so damn hot).
The only time I look at a woman's ass and it isn't wearing a thong is if its no other alternative, like a hot celebrity showing off her ass in a Game of thrones episode or something, but the moment that celebrity exposes her ass in a thong instead i never look back to her fully naked ass pics or vids.